The development of technology enables the manufacturing of smaller and smaller wireless communication devices. When the size of the device becomes smaller, this restricts the size of the display and keyboard with which the device is provided. In this case the size of the device compared to the desired size of the display and keyboard becomes a problem.
From the point of view of a user, a larger display is more informative and it is easier to use a larger keyboard (or larger keys) In other words, users want small devices whose size, however, makes them nice enough to use.
Conventionally some mobile telephone models, such as Nokia 7650, adopt a keyboard slide solution, where the keyboard is covered by a sliding cover. The sliding cover is slid away and the keyboard is uncovered, when the user wants to use the keyboard. In this case the problem is that the keyboard and the sliding cover take up a fair amount of space even when they are not used.
In other mobile telephone models, such as Nokia 6820, instead of a sliding cover covering the keyboard, a keyboard is arranged on the underside of a cover covering a body part. The cover is hinged to the body part, which also provides a keyboard. When the cover is opened, a display and the keyboard in the body part located on the right side of the display are uncovered. The hinged cover is turned past the display upside down to the left side of the display, in which case the keyboard on the underside of the cover is located on the left side of the display. Thus in this mobile telephone the keyboard is located on both-sides of the display, which allows using the keys conveniently by both hands. However, the solution makes the mobile telephone rather thick.
WO 01/42891 A1 discloses a solution, where a display and a keyboard manufactured of a flexible material have been rolled within the mobile telephone. When a user wants to use the keyboard and display, the mobile telephone is expanded by rolling out the display and keyboard from the roll. However, the solution presented is rather sensitive in terms of the support of the display and keyboard.